Apparatus to test for the presence of one only thread in textile machines

Abstract

To determine if a thread pick-up device, to pick up broken or run-out thread in thread spooling machines, has located therein only a single strand of thread, the thread is passed through a test gap which provides pulses each time the test gap senses that a discrete strand of thread is passed therethrough, the pulses being applied to a counter, the counter controlling operation of the device so that, if a ONE count is received, the thread has been properly picked up; if no count, or more than one count have been received, the thread pick-up operation is controlled, for example, by repeating the pick-up operation, or cutting the thread at the end of the pick-up operation, and repeating, to ensure presence of only a single thread in the pick-up device. Sensing of the thread becomes, therefore, independent of yarn size, thickness, or localized changes in diameter.

I claim: 
     
       1. Apparatus to test for the presence of one only discrete strand of thread being picked up from a yarn supply comprising means (10, 10') defining a test gap (12);   means (6, 7) picking up thread from the supply and placing it in the test gap;   means (20, 21; 30, 31) sensing the presence of thread (9, 9') in the test gap (12) and providing an output signal each time when the presence of a discrete strand of thread (9, 9') in said test gap is being sensed, and   a counter (24) controlled by the output signals from the sensing means, and algebraically counting the number to discrete threads (9, 9') passing through the test gap (12), the counter (24) providing an output signal when the count number is other than a predetermined value.   
     
     
       2. Apparatus according to claim 1, wherein the counter provides an output control signal when the count number exceeds unity. 
     
     
       3. Apparatus according to claim 1, further comprising a thread cutter (26) located with respect to the threads to cut the threads, and controlled by an output from the counter (24), if the count number exceeds unity. 
     
     
       4. Apparatus according to claim 1, further comprising means (11) movably supporting the test gap defining means (10, 10') and moving said test gap defining means in a direction having a vector component extending transversely to the major directions of the threads being picked up. 
     
     
       5. In automatic thread spooling machines, defect sensing and clearing mechanism (2), comprising pick-up means (6, 7) picking up loose thread ends from spools (4) on the spooling machine;   means (10, 10') defining a test gap (12);   means (20, 21; 30, 31) sensing presence of thread in the test gap;   means (11) movably supporting the test gap defining means (10, 10') for movement essentially transverse to the major directions of the threads which have been picked up by said pick-up means (6);   counter means (24) connected to and controlled by said sensing means to count the number of discrete strands of thread sensed by said sensing means upon relative movement between the thread and the test gap defining means; and means (24'; 25, 26) evaluating the count of the counter means.   
     
     
       6. Spooling machine according to claim 5, further comprising a thread cutter (26) located transversely to threads leading to the pick-up means (6) and operated and controlled by the means evaluating the count from the counter (24) if the count is other than ONE. 
     
     
       7. Spooling machine according to claim 6, wherein the means defining the test gap comprises a sensing head having an open and a closed end, movable essentially transversely to the major extent of the threads to an extreme position in which any thread being picked up is located at the closed end; and wherein the cutter means (26) is located adjacent the closed end of the sensing head, to cut all threads adjacent said closed end.   
     
     
       8. Spooling machine according to claim 5, further comprising means (2') to re-initiate activation of said pick-up means (6) when a count other than ONE is sensed by said count evaluation means. 
     
     
       9. Spooling machine according to claim 5, wherein the sensing means is an optical gate (20, 21). 
     
     
       10. Spooling machine according to claim 5, wherein the sensing means comprises an oscillator (30) and spaced capacitor plates (31) connected to the oscillator, the space between said plates forming said test gap. 
     
     
       11. Spooling machine according to claim 5, further comprising OFF switch means (27) disabling and re-setting the counter after movement of the means defining the test gap transverse to the major extent of the threads.